50 Years of Real-Life Ray Guns

Fifty years ago this Sunday, Theodore Maiman and his fellow scientists at Hughes Research Laboratory shined a high-power flash lamp on a ruby rod, triggering a beam of coherent light: the first laser. It wasn’t long before the Pentagon started dreaming up military applications, and futurists were predicting that our soldiers would all get ray guns. Well, not quite. But lasers have revolutionized the U.S. military — changing the way it targets bombs, scares off insurgents, and, yes, blows stuff to bits. Here are some of the greatest hits (and biggest misses) from the first half-century of military lasers.

Early researchers like Maiman didn’t think lasers were a tool of war. Air Force Colonel Joseph Davis Jr. had other ideas. It was the early days of the conflict in Vietnam, and U.S. bombs were going horribly off track — falling an average of 420 feet from their targets.

Davis gave Texas Instruments a $99,000 contract to see if lasers could make the bombs more accurate. The concept involved two airplanes: One fired a laser, “illuminating” a target; the other dropped a bomb that honed in on the light. And it worked. By the early ’70s, these laser-guided “Paveway” bombs landed within 23 feet of their targets — almost a 20-fold improvement over the old-school munitions. With that, the era of the “smart bomb” began.

Today’s precision-guided armaments can target a particular room of a particular house, or nail a moving car. Laser-guided missiles and bombs have become drones’ weapons of choice. But no war saw more smart bombs used than Vietnam. The United States wound up dropping 28,000 Paveways. But “they did not save the United States from defeat,” historian Max Boot notes. “A guerrilla foe hiding in the jungles was not very vulnerable to air attack.”

Bright lights have been used since World War II to distract and disorient enemies. Lasers — shining in a single direction, on a single wavelength — not only made these so-called “dazzler” weapons more powerful. They made ‘em small enough for a soldier to carry on patrol.

In 2006, the Army rushed 2,000 laser dazzlers into the field, to give troops at checkpoints a supposedly safer way to warn oncoming drivers to stop. But the dazzlers weren’t completely harmless. Over a five-month period in 2008 and 2009, a single unit in Iraq reported 14 laser “friendly fire” injuries. Three soldiers had to be medically evacuated out of the country, and one is now blind in one eye.

On March 26, 1983, just three days after Ronald Reagan announced his “Star Wars” missile defense plan, the U.S. military tested what might go down as the nuttiest anti-missile machine ever: a giant laser, powered by a nuclear bomb and its cascade of x-rays.

The brainchild of Manhattan Project physicist Edward Teller, Project Excalibur was supposed to fire off atomic-powered lasers from land or space at incoming missiles. There was just one problem — studying the laser proved difficult because the bomb kept destroying its sensors at the Nevada Test Site’s underground facility before scientists could receive the data.

Teller remained undaunted, however. He was convinced that his “Super-Excalibur,” powerful enough to destroy the entire Soviet nuclear arsenal, was about to enter the “engineering phase.” That helped inspire Reagan’s Star Wars vision. But 27 years later, the nuke-‘n’-laser combo is still just a dream. Or a nightmare. –Olivia Koski

As if Teller’s vision of bomb-powered lasers wasn’t enough, he also convinced the powers that be that it would be a good idea to put lasers on planes. More successful than his laser bomb idea, the Airborne Laser Laboratory shot down a drone on May 2, 1981, at White Sands Missile Range. A couple of years later, in 1983, it blasted some Sidewinder air-to-air missiles. Now, it sits in a museum at Wright-Patterson Air Force Base in Dayton, Ohio. The ALL was perceived as merely a proof-of-concept system, not practical for the battlefield.

But, wait, this story feels all-too familiar! Thirteen years later, in 1996, the Air Force awarded a $1.1 billion dollar contract to build a souped-up version of the Airborne Laser Laboratory. Using a bigger plane, and a more powerful chemical laser, they called it the Airborne Laser. “We are taking the first major step towards giving the American people their first light saber,” the head of the Missile Defense Agency proclaimed.

The Nuclear Test Ban Treaty was adopted by the United Nations in 1996. Which means it’s no longer cool for the United States to set off nukes underground. So how do you make sure the H-bombs are still working? Simulation — and the world’s biggest, most powerful laser. The National Ignition Facility is designed to fire off 192 giant lasers onto a target the size of a BB, and filled with hydrogen fuel. The result: heat and pressure of a kind only seen inside star cores and nuclear weapons. Using NIF’s data, supercomputers should be able to model a nuclear explosion — without dropping the bomb.

Oh, don’t worry. It only looks like a giant death ray. In reality, the Air Force is just trying to take some good pictures with its Starfire Optical Range. (Later on, they’ll get to the satellite-blasting energy weapon.)

Hot and cold pockets of air change the speed of light as it moves through the atmosphere. That makes stars appear to twinkle and creates a major challenge for researchers trying to get a clear view of objects in space. Starfire’s answer: Shoot a laser 56 miles into the mesosphere and measure the distortion. Then adjust the laser’s mirrors until the beam is back in focus. Whatever optical tweaks correct the beam will also focus a telescope.

The images from Starfire are 40 times sharper than uncorrected pics. Today, that aids astronomers; someday, maybe generals. “We don’t hide the fact that it could help build an anti-satellite weapon,” Colonel Gregory Vansuch, chief of the installation, told me a few years back. A big laser like Starfire’s could aim a satellite-killing missile — or blind the satellite by itself. Not that the U.S. military has any plans to do so. No, seriously! They swear!

No energy weapon has blasted more stuff out of the sky than the Tactical High Energy Laser. Developed in the late 1990s and early 2000s by the American and Israeli governments, the chemical-powered laser blasted 46 Katyusha rockets, artillery shells and mortars out of the sky. “All my career, I’ve been interested in fielding lasers,” Jeff Sollee, a veteran Northrop Grumman laser scientist, once told me. “THEL was as close as they come.”

But generating the megawatts of laser power required for THEL — known in Israel as “Nautilus” — meant brewing up hundreds of gallons of toxic chemicals, like ethylene and nitrogen trifluoride. The weapons grew bulky; one proposed small-scale version was supposed to be kept in a mere eight cargo containers, each 40 feet long. Needless to say, the project was abandoned.

But it hasn’t been forgotten. In 2008, a group of citizens from the Israeli town of Sderot, long under assault from Hamas rockets, tried to force the government to set up the energy weapon defense — by taking prominent officials to court. The lawsuit didn’t succeed, either.

Military lasermen figured out a long time ago how to build really, really strong ray guns. Making those blasters compact enough to be battlefield-useful — that’s been the tough part. Or at least it was, until early last year, when researchers at Northrop Grumman’s lab, just south of Los Angeles, started firing off a military-strength laser that could one day be configured into a laser weapon that’s ready for war.

Instead of the typical vats of toxic chemicals used to excite the light, Northrop’s guys used relatively small chains of garnet crystals. The result: the first “solid sate” laser that hit 100,000 watts — what’s considered weapons grade. It’ll still take at least $100 million and years of development to get an honest-to-goodness blaster. The solid state laser starts test-firing at White Sands Missile Range in New Mexico later on this year.

On Oct. 8, 2005, a Volkswagen managed to drive itself 128 miles across the Mojave Desert, to win Darpa’s “Grand Challenge” robot rally. Without lasers, that robo-SUV, nicknamed Stanley, never would’ve left the starting line. Perched atop the vehicle were five LIDAR (LIght Detection and Ranging) units. Shooting out laser pulses — and measuring the return — five times a second, the machines helped assemble an image of the course for the robot. Then Stanley could drive, without getting stuck in the sand. Troops use similar laser rangefinding techniques every day, to pinpoint targets’ locations. But for now, at least, their Humvees still have to be driven by human hands.

Imagine an energy weapon that can keep firing forever — and adapt its beam to the air around it. That’s the promise of the “Free Electron Laser.” And, depending on how you look at it, the FEL is either the biggest boondoggle in the history of military energy weapons, or the “Holy Grail of lasers.”

Lasers all work in pretty much the same way: Excite certain kinds of atoms, and light particles radiate out. Which slice of the spectrum depends on the “gain medium” — the type of atoms — you use to generate the beam. Those garnet crystals produce one laser wavelength; the chemicals, another. A FEL, on the other hand, doesn’t have a gain medium at all. It uses a turbocharged stream of electrons to kick-start its reaction instead. And that lets the FEL fire along many different wavelengths — and for a long, long time.

At least, that’s the theory. In practice, FELs have been hard to build. During the Star Wars era, the Defense Department sank 10 years and a half a billion into a FEL. All it could only muster a meager 11 watts — less than a typical lightbulb. More recently, however, FELs have hit more than 14,000 watts. The Navy has handed out contracts to begin design work on a weapons-grade “Holy Grail.”